Synchronizing device



J. D. HITCHCOCK 2,478,922

SYNCHRONIZING DEVICE Filed Jan. 15, 194e Arrow/Vey Patented ug. 16, i949 SYNCHRONIZING DEVICE Judge D. Hitchcock, United States Army,

Atlanta, Ga.

Application January 15, 194.6, Serial No. 641,360

Y 4`c1aims. (ci. rvs-53.1) (Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 O. G. 757) The invention described herein maybe manufactured and used by or for the Government for governmental purposes, without the payment of any royalty thereon.

This invention relatesto teletypewriter apparatus, and more particularly to improvements in typing reperforators used in connection with such apparatus. Y

In reperforators, for some-reason, it often happens that the normal start and stop impulses do not arrive at the selector magnets at the proper time; and it has been necessary to produce articial start and stop impulses somewhat shorter than normal start and stop impulses and to superimpose these artificial impulses on to but within the limits of the normal start and stop impulses in such a way as to control the selector magnets. The productionof the artificial start and stop impulses have heretofore been accomplished by an electronic apparatus having seven relays with associated resistors, condensers, etc., which apparatus is objectionable because it is complicated and expensive.

It is, therefore, an object of this invention to provide a mechanical synchronizer for a reperforator to produce artificial start and stop .impulses. The mechanical synchronizer is simpler, cheaper, more compact and more reliable than the electronic apparatus heretofore used for the same purpose. The mechanical synchronizer hereinafter described will satisfactorily perform Y any and all functions performed by the seven relays itis designed to replace. It will also not only assure that the same number of characters are perforated as were transmitted, but will decrease the number of errors on any message received by radio teletype when errors are caused by imperfect radio reception.

The above and other objects are attained by the novel arrangement and construction hereinafter described and illustrated by the accompanying drawings, forming a part hereof, and in which:

Fig. 1 is an elevational view of a mechanical synchronizer embodying the invention.

Fig. 2 is an elevational view of a start cam and start contacts.

Fig. 3 is an elevational view of a stop cam and stop contacts.

Fig. 4 is a schematic wiring diagram of the apparatus.

Fig. 5 is a schematic diagram of a clutch release circuit.

Fig. 6 is a perspective view of the selector cam sleeve of a standard typing reperforator as used with this invention.

Referring to Fig. 4, the stop contacts I and 2 are connected to the armature 3 and to the mark contact of a receive relay 6 so that when the stop contacts are closed they close the selector 2 magnet circuit even if the receive 'relay is inea spacing condition. f

The start contacts 4 and Y5 are connected inseries with the receive relayarmature 3 and selector magnets 'I so thatwhen` they open, the selector magnet circuit is open even if thevreceive relay is in a marking condition.

The synchronizer is mountedon the base of ya reperforator and is supported by a bracket I'I provided with a bearing I8 in which is journalled a cam sleeve shaft 8, to which is xed .a cam sleeve shaft gear 9. Acam sleeve I0 is mounted on one end of the cam -sleeve shaft and is driven by two friction clutches 20 and 2|. Fixed to the cam sleeve are the stop cam-22, start cam 23, and stop arm 24. 'i l Mounted on release bracket I3 is release lever I I controlled by release magnets I2, also mounted on release bracket I3: A' stop .contact lever I5 actuated by .the stop cam controls the stop contacts I and 2 and a start contact lever IS controls the start contacts 4 and 5. (See Figs. 1, 2, and 3).

As stated above the mechanical synchronizer is an attachment designed to replace a number of relays of the usual electronic synchronizer, and is mounted so that cam sleeve shaft gear 9 is actuated by a gear on the reperforator base which in turn is actuated by a gear on the reperforator.

Figure 6 shows the selector cam sleeve 45 of a main shaft 44 of a standard typing reperforator. Machines of this type are manufactured by the Teletype Corporation of Chicago, Illinois, under model number FPR 51-1193 (other types, not appreciably different are the FPR 23 series). A detailed description of these machines will be found in Bulletin No. 171, Issue 1, May 1941, Teletype Corporation, Chicago, Illinois.

In operation, assuming that the typing reperforator is in operation, the following sequence of operation starts just before the clutch throwout lever 43 operates the clutch lever contacts 30, 3l also on the reperforator (Fig. 5). At Vthis time the release magnets l2 are deenergized, the release lever II is held in its downward position by a spring. the stop arm 24 is resting against the release lever II, the cam sleeve is standing still and the stop contact lever I5 and start contact lever I6 are resting on the high part of their respective cams. The stop contacts I and 2 are open and the start contacts 4 and 5 are closed.

The clutch throwout lever 43 of the reperforator closes the clutch lever contacts 30, 3l, the release magnets I2 are energized, and operates the release lever II upward, which releases the release stop arm 24. The cam sleeve starts rotating, and stop -contact lever I5 rides into the indent 4I of stop cam 22. The stop contacts I, 2 close, starting the stop impulse; the clutch lever contacts 30, 3| then open and the release magnets 3 I2 are de -energized, and the release lever Il is pulled toa downward;position??by.l a spring. The stop contact lever I5 then rides onto the high part of the stop cam 22 and opens the stop contacts, and the stop impulse ends.

The start contact lever I6 then ridesintosindenii 42 of start cam 23 and the start contacts. 4, 5. open, starting the start impulse. Start Contact lever 46 rides on the high part of start cam 23 and the start contacts closeiending tl'ie'start im.- pulse. The cam sleeve continues to rotate until stop arm 24 strikes against the release lever l I`, when the cam sleeve I0 stops rotating; andastands still until the release magnets are again en;- ergized, L

What claimedlis 1'. A synchronizing device for aateletypewriter reperforatorpr comprising a shaft,.a.start. cam; and a` stop cammountedomtheshaft a receive relay havingA a. marking and' spacing condition, a selector. magnet..circuitstop contacts controlled by the stop cam so thattheyr closethefselector magnetcircuit eveniflthereceive relay is-inaspacing condition, and start:4 contacts: controlled bythe start caml so thaty they: open the? selectorl magnet circuit even if the'receive relay is inl amarking condition. Y

21 A synchronizing. device. fon a teletypewriter reperforator, comprising a.shaft,. means to rotate the shaft,l atreceivefrelay having a marking and spacing condition, a selector magnet circuit', stopcontaots. a: stop= cam@ mounted on'l the shaft to. control. the@ sten contacts sof that they.V close the selector. magnet circuitI everr if. the'I receive relay isdn af spacing;conditiom start contacts, and

' reperforator, comprising a shaft, a receive relay having, an armature with a spacing and marking condition, a` selector magnet circuit, a stop cam and a start cam mounted on the shaft, means to rotate2thefshattais'top arm to prevent rotation of thecams, a release magnet adapted to move the' stop arm to enable the cams to rotate, start contactsinfserieswlth said armature and selector magnetf circuitlisa' that the selector magnet circuit Will be open even if the receive relay is in a marking) condition,.. and. stop contacts connected to. the armature andmarlcl contact ofA the. receive relay tor close thefselector magnet circuit evenl if the receive relay is in a spacingcondition.v

4t. In a synchronizing device for aJ teletypewriter. reperforator, a'` shaft meansto rotate the shaft@ astop cam and'. a, star-t.` cam on. the shaft; stop contacts controlled by the stop cam, start contacts controlledY byfthelstartcampa stop arm to. prevent rotationf on the cams. a. release'magnet adapted tomove thel stoparm to a position to2 enable: the camse to` rotatesv saidf stop contacts and: ai receive; relay having an. armature: andr at least a mark-contact: said startcontacts being; in serieswith saldi armaturav and the stopl contacts being; inx parallelzwlthl the armature and.l mark Contact.

. JUDGEDLHISICHCGCK,

Noreferencesscited; 

